1. Field of the Invention
Disclosed herein are spinal decompression and traction systems and methods related to the field of spinal treatment. More particularly, certain embodiments disclosed herein relate to cervical and thoracic spinal decompression and traction systems having a plurality of inflatable bladders and methods of use that maintain a normal lordotic curve and counter hyper-kyphosis of the upper thoracic spine.
2. Description of the Related Art
Cervical pain is one of the most common health-related complaints. When there are no neurological deficits, symptomatic relief of pain is often sought with either non-steroidal analgesics, or various physical therapy modalities, including cervical traction. Most traction has consisted of axial linear distraction employing various head/chin straps and weights of 20 to 25 pounds. Such traction tends to straighten the cervical spine and often results in TMJ pain.
The undamaged cervical spine normally defines a forward or lordotic curve of about 43° (measured from C2-C7) whereby weight is distributed on hard individual bony articular surfaces in the posterior and soft intervertebral discs to the anterior. Without such a forward curve in the cervical spine, weight of the head transfers forward onto the soft non-bony intervertebral discs and vertebral bodies causing discs to dehydrate, wear, degenerate and protrude into the anterior subarachnoid space. As vertebral bodies bear uneven stress, spurs and osteophytes form. Additionally, individuals with lost or reversed (buckled) cervical spinal curves eventually exhibit a significant loss of natural joint movement, further limiting the normal canaliculus seepage and imbibition of adjacent fluids via vertebral end plates and annuli. Without such nutrient rich fluids the discs continue to dehydrate, further weakening the discs, resulting in a further loss of mobility, degeneration and possible nerve damage. Active nutrient transport is particularly important because the intervertebral discs' indigenous vascular supply often disappears at approximately 20 years of age.
Further, as the cervical spine is forced into flexion and the lordotic curve is reversed, the dura, cord and nerve-roots are drawn out; the root-sleeves come into contact with the pedicles, and the nerve roots with the inner surfaces of the sleeves. During extension (lordotic curve recovery) the dura, cord and nerve-roots in the cervical canal are slack; the root-sleeves have lost contact with the pedicles and the nerve-roots with the inner surfaces of the sleeves.
Axial/Linear/Longitudinal traction has long been employed to decompress cervical joints of the spine. Typically the head is pulled, pried, lifted or otherwise separated from the thorax along the Y axis (+Y axis translation or elevation translation). Ostensibly, to pry the joints apart at the posterior, forward flexion (+X axis rotation) is often employed in conjunction with or as an unavoidable component of linear traction. Linear traction or elevation translation applied to a curved column decreases or removes the curve. Likewise, adding the component of flexion or +rotation about the X axis, would apply a buckling force to the cervical spine and have the effect of reversing the curve (−Z axis translation). These forces, powerful enough to separate the spinal joints, are unfortunately antithetical to the natural geometry and biomechanics of the human cervical spine. The anchor points commonly used in Axial/Linear/Longitudinal traction are the head as it is pulled away from the thorax and/or the trapezius muscles as the thorax is pushed away from the restrained head. U.S. Pat. No. 4,805,603 to Cumberland describes a method where the head and thorax are separated by two platforms with an expanding air chamber between the two platforms. These methods, due to their linear function reduce, remove or reverse the proper cervical curve. U.S. Pat. No. 6,506,174 to Saunders also describes a linear traction system.
Some alternatives to axial/linear/longitudinal traction for disc, joint and nerve decompression seek to maintain a normal lordotic curve. For example, U.S. Pat. Nos. 5,382,226; 5,569,176; 5,713,841; 5,906,586; 7,060,085; 8,029,453; and D508,566S to Graham, each of which is hereby incorporated by reference herein in its entirety, disclose some embodiments of systems for decompression. In two IRB studies utilizing multiple MRI's, an embodiment of the disclosed systems showed a consistent ability to draw bulging disc material back toward the disc proper and away from the subarachnoid space and spinal cord while simultaneously enhancing or restoring the cervical lordotic curve during and after one 20 minute treatment. Patients reported immediate symptomatic relief of cervical pain. However, there exists a need for improved decompression systems that also address hyper-kyphosis of the upper thoracic spine.